1. Field of the Invention
The present invention relates to a spindle motor and a hard disk drive including the same.
2. Description of the Related Art
A fixed shaft-type spindle motor in which a shaft having excellent vibration characteristics is fixed to a case of a hard disk driving device is generally mounted in an information recording and reproducing device such as a hard disk driving device for a server.
That is, the shaft may be fixedly installed in the spindle motor mounted in a hard disk driving device for a server in order to prevent information recorded on the disk from being damaged and becoming unrecordable or unreadable due to an increase in an amplitude of vibration of a rotor caused by external impacts.
As described above, in the case in which the fixed shaft-type is installed, upper and lower thrust members are fixedly attached to the shaft.
However, in the case in which the shaft is fixedly attached to the lower thrust member and the lower thrust member is fixed to a base, since the shaft serving as a rotating shaft should be firmly fixed, the lower thrust member may be relatively thick and fixed to an outer peripheral surface of the shaft in a scheme such as a press-fitting scheme, a bonding scheme, a sliding scheme, or the like.
Meanwhile, in accordance with the recent trend for thinness in hard disk drives, the spindle motor used therein has been thinned. However, in the case in which the lower thrust member is relatively thick, as described above, the thinness of the spindle motor has been hindered and a bearing span is inevitably shortened, such that motor performance may be deteriorated.
Related Art Document described below relates to a fixed shaft-type spindle motor and includes upper and lower thrust members (230 and 220). In FIG. 4 thereof, in the case of a structure in which a shaft (210) is fixed to the thrust member (220), the shaft (210) may only be firmly fixed to the lower thrust member (220) if the lower thrust member 220 is relatively thick.